Team Members:

• Dinesh Prasanth Moluguwan Krishnamoorthy – dmolugu
• Tyler Cannon – tjcannon
• Tianpei Xia – txia4
• Okoilu Ruth – rookoilu

List of Files Changed:

• BasicBufferMgr.java
• Buffer.java
• LogIterator.java
• LogMgr.java
• CheckpointRecord.java
• CommitRecord.java
• LogRecord.java
• LogRecordForwardIterator.java //the new class we added
• LogRecordIterator.java
• RecoveryMgr.java
• RollbackRecord.java
• SetIntRecord.java
• SetStringRecord.java
• StartRecord.java

Sample code for Testing Iterator:

SimpleDB.init("simpleDB");
Block blk1 = new Block("filename", 1);
Block blk2 = new Block("filename 2", 4);

BufferMgr bm = SimpleDB.bufferMgr();

Buffer buff1 = bm.pin(blk1);
Buffer buff2 = bm.pin(blk2);

RecoveryMgr rm = new RecoveryMgr(123);

int lsn = rm.setInt(buff1, 4, 1234);
buff1.setInt(4, 1234, 123, lsn);

int lsn2 = rm.setString(buff2, 10, "dinesh");
buff2.setString(10, "dinesh", 123, lsn2);

rm.commit();



LogRecordIterator iter = new LogRecordIterator();
while(iter.hasNext()) {
	System.out.println("Backward reading: " + iter.next());
	
}

LogRecordForwardIterator forwardIter = new LogRecordForwardIterator(iter);
while(forwardIter.hasNext()) {
	System.out.println("Forward Reading: " + forwardIter.next());
}

Sample Code to test Recovery:

SimpleDB.init("abcd");

bm = SimpleDB.bufferMgr();

Buffer buff = bm.pin(blk);

buff.setInt(14, 4444, 1, -1);
buff.setString(32, "oldvalue", 1, -1);

bm.unpin(buff);




// Can't use 1 as it's being used for intialization
int t1 = 22;
int t2 = 33;
RecoveryMgr rm1 = new RecoveryMgr(t1);
RecoveryMgr rm2 = new RecoveryMgr(t2);

buff = bm.pin(blk);

int lsn = rm1.setInt(buff, 14, 1234);
buff.setInt(14, 1234, t1, lsn);

lsn = rm2.setString(buff, 32, "newvalue");
buff.setString(32, "newvalue", t2, lsn);

bm.unpin(buff);

if (buff.getInt(14) == 1234 && buff.getString(32).equals("newvalue"))
	System.out.println("New values are set");

bm.unpin(buff);
rm2.commit();

rm1.recover(); 
buff = bm.pin(blk);
if (buff.getInt(14) == 4444 && buff.getString(32).equals("newvalue"))
	System.out.println("Recovered properly");

bm.unpin(buff);